1. Field of the Invention
This invention relates generally to a hot water supply system, and particularly to a system that heat exchanges water with a heated refrigerant in a heat exchanger while maintaining a difference in temperature between refrigerant exhausted from the heat exchanger and water input into the heat exchanger within a predetermined temperature range.
2. Related Art
A typical hot water supply system is described in, for example, Japanese Utility Model Laid-Open No. Hei. 6-73652. In the described system, water is heated by an electric heater and is then stored in a heat insulating tank. As the water must be heated by the electric heater, overall system power requirements are increased. Therefore, such a hot water supply system generates hot water at night to minimize electricity costs.
Therefore, it is an object of the present invention to provide a hot water supply system in which the amount of power required to generate hot water is reduced.
The present invention provides a heating system in which a refrigerant flow on a high-pressure side of a heat pump cycle and a hot water flow are opposite one another. Water heated by the high-pressure side refrigerant is stored in heat insulating tanks.
In the above-described arrangement, water is heated by heat absorbed from the atmosphere and by a supercritical heat pump cycle of high heat exchange efficiency, so that power required to heat the water can be minimized. Therefore, it is possible to generate hot water by using a minimum amount of power, as hot water may be generated when demand so requires, without the need for storing hot water for daytime use. Moreover, as heat insulating tanks are not required for storing water heated during nighttime hours for daytime use, a much smaller-scale hot water supply system can be implemented.